feat(engine): restructure configuration and upload install.sh

BREAKING: The node specific configuration for k3s is now located
under its own "config" key in the YAML.

Please refer to the examples in the "examples" directory to figure
out how to modify your configuration.

cmd/up.go

@@ -1,6 +1,11 @@
 package cmd
 
 import (
+	"os"
+	"time"
+
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/log"
 	"github.com/spf13/cobra"
 
 	"github.com/nicklasfrahm/k3se/pkg/ops"
@@ -17,12 +22,21 @@ by passing a path to the configuration file as a CLI
 argument.`,
 	Args: cobra.MaximumNArgs(1),
 	RunE: func(cmd *cobra.Command, args []string) error {
+		logger := log.Output(zerolog.ConsoleWriter{
+			Out:        os.Stderr,
+			TimeFormat: time.RFC3339,
+		})
+
+		opts := []ops.Option{
+			ops.WithLogger(&logger),
+		}
+
 		// Use manual override for config path if provided.
 		if len(args) == 1 {
-			return ops.Up(ops.WithConfigPath(args[0]))
+			opts = append(opts, ops.WithConfigPath(args[0]))
 		}
 
-		return ops.Up()
+		return ops.Up(opts...)
 	},
 }
 

pkg/engine/engine.go

@@ -0,0 +1,79 @@
+package engine
+
+import (
+	"bytes"
+	"io/ioutil"
+	"net/http"
+	"sync"
+
+	"github.com/rs/zerolog"
+)
+
+const (
+	InstallerURL = "https://get.k3s.io"
+)
+
+// Engine is a type that encapsulates parts of the installation logic.
+type Engine struct {
+	Logger *zerolog.Logger
+
+	sync.Mutex
+	installer []byte
+}
+
+// New creates a new Engine.
+func New(options ...Option) (*Engine, error) {
+	opts, err := GetDefaultOptions().Apply(options...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Engine{
+		Logger: opts.Logger,
+	}, nil
+}
+
+// Installer returns the downloaded the k3s installer.
+func (e *Engine) Installer() ([]byte, error) {
+	// Lock engine to prevent concurrent access to installer cache.
+	e.Lock()
+
+	if len(e.installer) == 0 {
+		resp, err := http.Get(InstallerURL)
+		if err != nil {
+			return nil, err
+		}
+		defer resp.Body.Close()
+
+		e.installer, err = ioutil.ReadAll(resp.Body)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	e.Unlock()
+
+	return e.installer, nil
+}
+
+// Configure uploads the installer and the configuration
+// prior to a node prior to running the installation.
+func (e *Engine) Configure(node *Node) error {
+	installer, err := e.Installer()
+	if err != nil {
+		return err
+	}
+
+	if err := node.Upload("/tmp/k3se/install.sh", bytes.NewReader(installer)); err != nil {
+		return err
+	}
+
+	// TODO: Upload configuration and move it to appropriate location using "sudo".
+
+	return nil
+}
+
+// Cleanup removes all temporary files from the node.
+func (e *Engine) Cleanup(node *Node) error {
+	return node.Exec("rm -rf /tmp/k3se")
+}

pkg/engine/node.go

@@ -1,6 +1,9 @@
 package engine
 
 import (
+	"io"
+	"path/filepath"
+
 	"github.com/nicklasfrahm/k3se/pkg/sshx"
 )
 
@@ -45,3 +48,37 @@ func (node *Node) Disconnect() error {
 
 	return nil
 }
+
+// Upload writes the specified content to the remote file on the node.
+func (node *Node) Upload(dst string, src io.Reader) error {
+	// Get base directory for the file.
+	dir := filepath.Dir(dst)
+
+	// Create directory if it does not exist.
+	if err := node.Client.SFTP.Mkdir(dir); err != nil {
+		return err
+	}
+
+	// Upload file.
+	file, err := node.Client.SFTP.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	// Empty existing file.
+	if err := file.Truncate(0); err != nil {
+		return err
+	}
+
+	// Overwrite file content.
+	_, err = io.Copy(file, src)
+	return err
+}
+
+// Exec executes the specified command on the node.
+func (node *Node) Exec(cmd string) error {
+	// TODO: Implement this.
+
+	return nil
+}

pkg/engine/options.go

@@ -1,11 +1,9 @@
 package engine
 
 import (
-	"os"
 	"time"
 
 	"github.com/rs/zerolog"
-	"github.com/rs/zerolog/log"
 
 	"github.com/nicklasfrahm/k3se/pkg/sshx"
 )
@@ -34,10 +32,7 @@ func (o *Options) Apply(options ...Option) (*Options, error) {
 // GetDefaultOptions returns the default options
 // for all operations of this library.
 func GetDefaultOptions() *Options {
-	logger := log.Output(zerolog.ConsoleWriter{
-		Out:        os.Stderr,
-		TimeFormat: time.RFC3339,
-	})
+	logger := zerolog.Nop()
 
 	return &Options{
 		SSHProxy: nil,

pkg/ops/options.go

@@ -1,5 +1,7 @@
 package ops
 
+import "github.com/rs/zerolog"
+
 const (
 	// Program is used to configure the name of the configuration file.
 	Program = "k3se"
@@ -8,6 +10,7 @@ const (
 // Options contains the configuration for an operation.
 type Options struct {
 	ConfigPath string
+	Logger     *zerolog.Logger
 }
 
 // Option applies a configuration option
@@ -39,3 +42,11 @@ func WithConfigPath(configPath string) Option {
 		return nil
 	}
 }
+
+// WithLogger overrides the default logger.
+func WithLogger(logger *zerolog.Logger) Option {
+	return func(options *Options) error {
+		options.Logger = logger
+		return nil
+	}
+}

pkg/ops/up.go

@@ -21,6 +21,11 @@ func Up(options ...Option) error {
 		return err
 	}
 
+	eng, err := engine.New(engine.WithLogger(opts.Logger))
+	if err != nil {
+		return err
+	}
+
 	// Establish connection to proxy if host is specified.
 	var sshProxy *sshx.Client
 	if config.SSHProxy.Host != "" {
@@ -35,6 +40,10 @@ func Up(options ...Option) error {
 		if err := node.Connect(engine.WithSSHProxy(sshProxy)); err != nil {
 			return err
 		}
+
+		if err := eng.Configure(node); err != nil {
+			return err
+		}
 	}
 
 	// TODO: Create configuration file at /etc/rancher/k3s/config.yaml
@@ -48,9 +57,15 @@ func Up(options ...Option) error {
 	// TODO: Store state on server nodes to allow for configuration diffing later on.
 	// TODO: Fetch state from Git history.
 
-	// Disconnect from all nodes.
+	// Clean up and disconnect from all nodes.
 	for _, node := range nodes {
-		node.Disconnect()
+		if err := eng.Cleanup(node); err != nil {
+			return err
+		}
+
+		if err := node.Disconnect(); err != nil {
+			return err
+		}
 	}
 
 	return nil

pkg/sshx/options.go

@@ -1,11 +1,9 @@
 package sshx
 
 import (
-	"os"
 	"time"
 
 	"github.com/rs/zerolog"
-	"github.com/rs/zerolog/log"
 )
 
 // Options contains the configuration for an operation.
@@ -32,10 +30,7 @@ func (o *Options) Apply(options ...Option) (*Options, error) {
 // GetDefaultOptions returns the default options
 // for all operations of this library.
 func GetDefaultOptions() *Options {
-	logger := log.Output(zerolog.ConsoleWriter{
-		Out:        os.Stderr,
-		TimeFormat: time.RFC3339,
-	})
+	logger := zerolog.Nop()
 
 	return &Options{
 		Proxy:   nil,